A little-noticed data point at the back of a 216-page report released last week by the BIS shows the international agency has taken 349 metric tons of gold since December—allowing central banks to raise a record $14 billion.

The number surprised the market, which had assumed most central banks had retained their holdings of gold. Instead, the BIS data show that they have been entering these gold swaps—exchanging their gold with the BIS in return for cash, agreeing to repurchase the gold at a later date.

As the article notes, this has been going on for awhile, and these transactions don't directly impact the open gold market, as it's not as though this is gold just flooding the market.

Still, it signals a shift. It also signals a broader setback, perhaps, for advocates of gold-backed, hard currency.

The bottom line is that central banks still want flexibility, even if that means potentially-debased "paper" currencies.

Gold obviously has its rule, but in crunch time, and at the right price, it also gets sold.